mySQL Transactional Operations

In my experiennces using relational databases the concept of the "transaction" was key. The ability to "Lock" a table and then "Commit" the changes when the tranaction correctly completed was an important concept. If the proces in the "Update" failed then the transaction can be "rolled back" to the original state.

Lock

The concept of a "lock" is largely transparent to the user of most systems but it is a key feature to ensure that data integrity is maintained.

Commit

When all updates have been made to a database, all data is validated, the changes can finally be commited and the locks on the tables released.